Content deleted Content added
Blush30720 (talk | contribs) →Syntax: rearrange paragraphs |
m fix quot; repair |
||
| (26 intermediate revisions by 7 users not shown) | |||
Line 1:
{{Short description|GNU replacement for the Bourne shell}}
{{multiple issues|
{{
{{More refs|date=August 2025}}
{{Over-quotation|date=August 2025}}
}}
{{Use dmy dates|date=March 2014}}
{{Infobox software
Line 265 ⟶ 267:
| url = https://developer.mozilla.org/en-US/docs/Glossary/Character
| website = mozilla.org
| date = 11 July 2025
}}
</ref>
Line 333 ⟶ 336:
| quote = UNIX is case sensitive. Because UNIX is case sensitive, our shell scripts are also case sensitive.
| title = Mastering Unix Shell Scripting, 2e
| url = https://books.google.com/books?
}}
</ref>
Line 362 ⟶ 365:
BCPL is a precursor of the [[C (programming language) |C programming language]], in which Bash is written.
In [[C++]], a descendant of C, it's also true that "arrays start indexing from element 0."<ref>
{{Cite
| access-date = 25 August 2025
| author = Graham M. Seed
Line 370 ⟶ 373:
| publisher = [[Springer Science+Business Media]]
| title = An Introduction to Object-Oriented Programming in C++, 7.4 Array Indexing
| url = https://books.google.com/books?id=_lqj98AsnGAC&q=zeroth+element&pg=PA195
| isbn = 978-1-85233-450-5
| website = books.google.com▼
}}
</ref>
The array's name and index number are a synonym for the data's ___location in memory.<ref>
{{Cite
| access-date = 25 August 2025
| author = Graham M. Seed
Line 383 ⟶ 386:
| quote = The name of an array is a synonym for the memory ___location of the array.
| title = An Introduction to Object-Oriented Programming in C++, 7.12.1 One-Dimensional Arrays
| url = https://books.google.com/books?id=_lqj98AsnGAC&q=zeroth+element&pg=PA210
| isbn = 978-1-85233-450-5
| website = books.google.com▼
}}
</ref>
Line 500 ⟶ 503:
<!-- Important concepts:
[] stream of characters
[] delineate full commandlines (newline, semi-colon)
[] division into commands and parts of commands (optargs)
[] uses metacharacters
-->
<syntaxhighlight lang = text>
Line 514 ⟶ 520:
{{Blockquote
| syn{{dot}}tax '''1
{{Cite web
| access-date = 25 August 2025
Line 526 ⟶ 532:
When Bash reads a ''full commandline,'' the complete string is broken down according to a certain set of rules into individual units called ''"tokens."''
"Tokens" are identified using, and separated from each other using ''"metacharacters."'' (As of version 5.3:)
Line 535 ⟶ 541:
''"Blanks"'' are composed entirely of unquoted metacharacters, ''"operators"'' each contain at least one unquoted metacharacter and ''"words"'' may not include any unquoted metacharacters.
In practice, Bash breaks down ''full command strings'' into tokens or groups of tokens that ''do'' contain
From there it further breaks ''words'' down into more specific, meaningful pieces like command names, variable assignment statements, etc.
Line 1,156 ⟶ 1,162:
[ ] scripts execute the contents of a file in a subshell
-->
With the {{code| source}}, or synonymous {{code| .}} command, Bash reads and executes shell commands from any text file by name.<ref>
{{Cite web
| access-date = 26 August 2025
| publisher = [[Free Software Foundation, Inc.]]
| title = 4.1 Bourne Shell Builtins
}}
</ref>
=== Login and non-login shells <span class="anchor" id="Login and non-login shells"></span><span class="anchor" id="Login shells"></span><span class="anchor" id="Non-login shells"></span> ===
Line 1,735 ⟶ 1,750:
| quote = 19 :: SIGSTOP :: Stop, usually Ctrl + z
| title = Mastering Unix Shell Scripting, 2e
| url = https://books.google.com/books?
}}</ref>
When a process receives a SIGKILL, the process terminates immediately and messily.
Line 1,748 ⟶ 1,763:
| quote = Use KILL only as a last resort!
| title = Learning the bash Shell: Unix Shell Programming
| isbn = 978-0-596-55500-9
| url = https://books.google.com/books?hl=en&lr=&id=dzBCH3x6fYEC▼
}}</ref>
The SIGKILL signal cannot be blocked or handled.
Line 1,819 ⟶ 1,835:
| quote = In Korn shell the {{Mono |echo}} command recognizes these command options by default. In Bash shell we must add the {{Mono |-e}} switch to the {{Mono |echo}} command, {{Code| echo -e "\n"| bash}} for one new line.
| title = Mastering Unix Shell Scripting, 2e
| url = https://books.google.com/books?
}}</ref>
The list of options is not uniform across implementations, though {{mono|echo}} and {{mono|printf}} are both specified by POSIX.
Line 2,141 ⟶ 2,157:
| publisher = [[GNU Project]]
| title = Bash Reference Manual: 4.3.1: The Set Builtin
| url = https://www.gnu.org/software/bash/manual/html_node/The-Set-Builtin.html
▲/software/bash/manual/html_node/The-Set-Builtin.html
| website = [[Free Software Foundation, Inc.]]
}}</ref>
Line 2,320 ⟶ 2,335:
-->
{{Blockquote
| ITERATION: Sometimes programs are repeated indefinitely or until a specific outcome is reached. Each execution of the instructions is an
{{Cite web
| access-date = 15 August 2025
Line 2,327 ⟶ 2,342:
| url = https://onlinegrad.syracuse.edu/blog/coding-terms-for-beginners/
| website = syracuse.edu
| date = 13 January 2020
}}</ref>
| author =
Line 2,459 ⟶ 2,475:
| quote = Learning this now can save us a lot of pain and heartache later, especially....
| title = Mastering Linux Shell Scripting
| isbn = 978-1-78439-759-3
}}</ref>
| author = Mastering Linux Shell Scripting, by Andrew Mallett
Line 4,082 ⟶ 4,099:
Bash became the default shell on Apple's operating systems (i.e., MacOS) starting with OS X 10.3 Panther.<ref>[https://www.google.com/books/edition/Essential_Mac_OS_X_Panther_Server_Admini/zrI-U0KWj3cC?hl=en&gbpv=1&dq=bash&pg=PA189&printsec=frontcover Essential Mac OS S Panther Server Administration, pg 189]
</ref><ref>
{{Cite
| access-date = 8 August 2025
| archive-date = 2 March 2021
Line 4,100 ⟶ 4,117:
| url = https://books.google.com/books?id=dwIRERUpQPEC&q=bash+most+popular+unix+shell&pg=PA6
| url-status = live
}}
</ref>
| |||